package com.cms.common.lang;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;

import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;

import com.cms.common.util.RandomUtil;
import com.cms.common.util.StringUtil;


/** 验证码生成器. */
public class ValidateCodeHandle {
	private ByteArrayInputStream image;		//图像
	private String str;						//验证码

	public ValidateCodeHandle() {
		init();								//初始化属性
	}
	
	
	
	//****************************公共方法**************************

	/** 取得验证码图片. */
	public ByteArrayInputStream getImage() {
		return this.image;
	}

	/** 取得图片的验证码. */
	public String getString() {
		return this.str;
	}
	
	
	
	//****************************私有方法**************************

	/** 初始化. */
	private void init() {
		//在内存中创建图象
		int width			= 80;
		int height			= 20;
		BufferedImage image	= new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		
		//获取图形上下文
		Graphics g = image.getGraphics();
		
		//设定背景色
		g.setColor(getRandColor(200, 250));
		g.fillRect(0, 0, width, height);
		
		//设定字体
		g.setFont(new Font("微软雅黑", Font.PLAIN, 20));
		
		//随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
		g.setColor(getRandColor(160, 200));
		
		for (int i = 0; i < 155; i++) {
			int x	= RandomUtil.nextInt(width);
			int y	= RandomUtil.nextInt(height);
			int xl	= RandomUtil.nextInt(12);
			int yl	= RandomUtil.nextInt(12);
			g.drawLine(x, y, x + xl, y + yl);
		}
		
		//取随机产生的认证码(4位数字)
		StringBuilder sRand = new StringBuilder("");
		for (int i = 0; i < 4; i++) {
			String rand	= String.valueOf(RandomUtil.nextInt(10));
			sRand.append(rand);
			
			//将认证码显示到图象中
			g.setColor(new Color(20 + RandomUtil.nextInt(110), 20 + RandomUtil.nextInt(110), 20 + RandomUtil.nextInt(110)));
			//调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
			g.drawString(rand, 20 * i + 6, 18);
		}
		// 赋值验证码
		this.str = sRand.toString();

		//图象生效
		g.dispose();
		ByteArrayInputStream input		= null;
		ByteArrayOutputStream output	= new ByteArrayOutputStream();
		try {
			ImageOutputStream imageOut	= ImageIO.createImageOutputStream(output);
			ImageIO.write(image, "JPEG", imageOut);
			imageOut.close();
			input						= new ByteArrayInputStream(output.toByteArray());
		} catch (Exception e) {
			System.out.println(StringUtil.join("验证码图片产生出现错误：", e.toString()));
		}

		this.image	= input;/* 赋值图像 */
	}

	/** 给定范围获得随机颜色. */
	private Color getRandColor(int fc, int bc) {
		if (fc > 255) {
			fc	= 255;
		}
		if (bc > 255) {
			bc	= 255;
		}
		int r	= fc + RandomUtil.nextInt(bc - fc);
		int g	= fc + RandomUtil.nextInt(bc - fc);
		int b	= fc + RandomUtil.nextInt(bc - fc);
		return new Color(r, g, b);
	}

}